a must

a must

That which is requisite, necessary, or indispensable. I know this book is a difficult read, but it's an absolute must if you enjoy literature. Taking the introductory course is a must if you want to sign up for the advanced class.
See also: must

a must

A necessity; a requirement. For example, The Louvre is a must for visitors to Paris, or This book is a must for serious students of English. [Late 1800s]
See also: must

a must

verb
See also: must
References in periodicals archive ?
Embarrassing the A's again was a must for the Angels, who instead slipped six games behind the Seattle Mariners in the American League West with nine to play, and were on the brink of elimination from the wild-card race against the New York Yankees.
Instead, A must reduce its tax attributes, to the extent of its insolvency, in the following order: NOLs (including carryovers), general business credits, capital loss carryovers, basis reduction of its property and, finally, foreign tax credit carryovers (Sec.
To gain the advantage of solvency, A must demonstrate that the FMV of its assets exceeded the values shown on its balance sheet.